Zurich prosecutors said in a separate statement they were investigating a former chairman and a former board member at Aduno and three business associates and had searched homes and offices in the case on Tuesday. A spokeswoman confirmed Vincenz was one of the subjects of their investigation.

Vincenz had been the only chairman of Aduno until stepping down last year. He was not immediately available for comment.

The Swiss Financial Market Supervisory Authority (FINMA) said in December it had ended proceedings into former banking and insurance executive Vincenz, which became redundant following his resignation from financial institutions.

Vincenz has said the FINMA probe related to his handling of conflicts of interest while with Raiffeisen, Switzerland’s third-largest bank, and that he believed he had treated the potential conflicts with the necessary care. (Reporting by Michael Shields and Silke Koltrowitz, editing by Louise Heavens)